IBF, IBO, WBA, WBO heavyweight champion Anthony Joshua (21-0, 20 KOs), and his promoter Eddie Hearn, are standing firm with their position that a unification with WBC champion Deontay Wilder (40-0, 39 KOs) takes place on UK soil.

The three venues being targeted by Hearn include Wembley Stadium, Twickenham Stadium and the Olympic Stadium.

Joshua and his handlers recently sent over a guaranteed offer of $50 million to persuade Joshua to take the fight in the United States.

While Joshua was initially skeptical of the high offer, Hearn confirmed that it's legitimate and the money is there.

Even with $50 million on the table, Joshua is willing to make less money in order to face Wilder in the UK.

If Wilder wins, then Joshua is willing to make the rematch in the United States.

"It's the general opinion of myself, AJ and Rob McCracken [Joshua's trainer] that because of the status of AJ in the fight and what we've built over here in the U.K. that we should try and get it over here because he has earned the right for that fight over here," Hearn told Nick Parkinson.

"If Wilder wins, the rematch can be over there in America. We are going back and forth with talks at the moment and I'm confident we can make that fight. AJ appreciates he might not make as much money by fighting in the U.K. but realises that Wilder should be coming to the U.K. to fight first."

Joshua has grown accustomed to having massive crowds at his events, which recently range from 76-90,000 fans packing a stadium.

He doesn't like the idea of having his biggest fight before a watered down crowd of British fans.

"AJ asked me how many British fans could get tickets if the fight was in America and could get over and I said about 6,000 and that's after we have done 250,000 in three fights and it doesn't seem right," Hearn said.

"He's keen to do the fight in the U.K. and from Rob's point of view it's an advantage. If it's in September it gives us the ability to go outside and we would have to consider Cardiff [the Principality Stadium], Wembley, the Olympic Stadium, Twickenham and Old Trafford. AJ wants it in London preferably."